Kintner, William R
Henry Regnery Comapany, 1962
Buku Teks
Pentony, Devere E.
Chandler Pub. Co., 1962
Buku Teks
edited Archie Brown and Jack Gray
Holmes & Meier, 1979
Buku Teks
Bouscaren, Anthony Trawick
Henry Regnery Company, 1958
Buku Teks
Harbron, John D.
FRederick A. Praeger, 1963
Buku Teks